I've never seen the 4/06 and I find 2/27 more frequently than the 3/16. I did find some nice 5/15/12 Deviant Dales earlier this week. Yum
Good retailers will rotate their stock. Gabriel's has the 4/06, but it won't be put on the shelf until the older batches are depleted.
Unfortunately, just because someone sells craft beer does not mean they have knowledge. These people do not know how crucial it is for this beer to be fresh.
As much as many retailers would love to make old beer magically vanish and be replaced with fresh stuff, this isn't always possible. In the case of Endeavour (in certain markets), it may happen at some point. Silver Eagle is pretty good about swapping out old product for new stuff. Though their definition of "fresh" isn't always the same as ours. Ben E Keith (the largest craft distributor in TX, and the carrier of Endeavor for markets north of us), on the other hand, doesn't swap out product, PERIOD. And retailers can't just pull old product and let it sit in the back. We have to sell it. That's why the freshest batch of Endeavour hasn't been spotted on shelves anywhere.